The genomic understanding of cancer survival pathways poses new biotechnology challenges for the medical oncology of anti-cancer drug discovery and therapy development. For many new classes of anticancer agents, prediction of therapeutic response or resistance in a clinical trial can be made with a biopsy. This requires the simultaneous detection and quantification of multiple protein biomarkers on tissue specimens. Available technologies allow neither simultaneous detection nor exact quantification of multiple therapeutic target proteins in cancer specimens. Nanotechnology, using nanocrystals conjugated to high avidity directed antibodies, permits a rapid, simultaneous assessment and quantification of cancer biomarkers. We will optimize multicolor sets of antibody-linked quantum dots for candidate biomarkers as well as validated therapeutic decision biomarkers in breast cancer, colon adenoma, and prostate cancer. We plan to develop multiple nanoparticles (quantum dots) to detect and quantify protein biomarkers in human tumors, which will allow the exact selection of appropriate therapies for individual patients. This technology is of paramount importance to novel cancer drug discovery and development as well as the pharmacodynamic evaluation of in vivo "drug on target" in patient populations. The simultaneous detection of multiple proteins allows interrogation of entire signal transduction pathways in cancer tissues in response to novel agents. Ultimately, the use of quantum dot antibody nanotyping may allow the exact tailoring of specific therapies to individual patients.